A drug that can alleviate many of the symptoms of rheumatoid arthritis will cost £8,000 a year per patient, creating financial problems for NHS managers.

It is the second new rheumatoid arthritis drug to emerge within a month. The first, Leflumonide, costs £6,000 per year.

But as these are the first new drugs for the crippling and painful condition in a decade, the demand is likely to be enormous.

A study published in The Lancet confirms that infliximab, the first of a new class of such drugs, was highly effective in treating patients whose disease was not responding to conventional therapy.

Half given both infliximab and an existing treatment, methotrexate, reported their symptoms easing by one-fifth.

A third of those given the drugs said their symptoms were 50% better.

Doctors excited by possibilities

Dr Simon Burnet, a specialist registrar in rheumatology at Addenbroke's Hospital near Cambridge, said that doctors were very excited by the possibilities offered by infliximab, and another drug in the same class also under trial.

"I feel that the financial implications are not insurmountable, although the current treatment, methotrexate, costs next to nothing," he said.

Rheumatoid arthritis is a reaction by the body's own immune system to tissues surrounding the joints.

The drug works by targeting one of the key agents which causes the reaction, called tumour necrosis factor (TNF).

It is an antibody which attacks the TNF and stops it causing inflammation and damage.

The current front line therapy for the condition is methotrexate, which can cause highly unpleasant side effects.

Rheumatoid arthritis affects approximately one per cent of the population, and can lead to permanent disability, and even, in extreme cases, move to affect the major organs, causing life-threatening damage.